1. Field of the Invention
The present invention relates generally to optical fiber ribbon splitting tools, and more particularly, to optical fiber ribbon splitting tools operable for separating ribbons into one or more subsets of optical fibers and tools for use in splitting fiber ribbons at cable access points.
2. Technical Background
Fiber optic networks are being developed that include cable assemblies having network access points along the cable length for providing access to optical fibers within the cable. These cable access points serve as an entry point into a cable in order to handle, sever and split pre-selected optical fibers so that they may be withdrawn through the cable access point. The pre-selected optical fibers are typically preterminated and spliced to optical fibers of a tether, thus providing a tap or branch off of a cable used to extend the optical network. Cable assemblies including network access points are commonly used in Fiber-to-the-Premises (FTTP) applications. These cable assemblies are typically pre-engineered and include factory installed cable access points substantially encapsulated within flexible bodies, thus providing cable assemblies including flexible network access points, or “FlexNAPs.”
Cable assemblies may include various fiber optic cable types. The term “distribution cable” is commonly used to describe the cable that is accessed, and the term “tether” or “tether cable” is commonly used to describe the cable added at a network access point. A tether typically contains a lesser number of optical fibers than a distribution cable. One example of a fiber optic distribution cable used in a cable assembly includes a flat ribbon cable having at least one optical fiber ribbon therein. As is generally understood by those skilled in the art, optical fiber ribbons may be created by arranging a plurality of optical fibers in a planar relationship (e.g., twelve or twenty-four fibers) and extruding a common matrix coating, such as a UV curable acrylate material, about the arranged optical fibers. The distribution cable may further include at least one strength member arranged about parallel to the at least one optical fiber ribbon. Oftentimes, splicing or connectorization of the preterminated optical fibers requires that the optical fibers be reduced to a smaller subset. While this subset reduction may be readily accomplished with a stand-alone ribbon, subset reduction is exceedingly more difficult at a network access point at which access to the ribbon is limited.
Conventional ribbon splitting devices are not easily applied to cable assembly applications. Conventional devices generally include a housing and a reciprocal member formed of many parts mounted thereon. The reciprocal member is generally movable along a defined line of action when a pressing force (applied by a technician) is applied to a button or actuator. Ribbon receiving slots are typically arranged to receive a single optical fiber ribbon of a flat ribbon distribution cable. The reciprocal member typically includes a plurality of blades fastened thereto. The plurality of blades are designed to shear apart a subset of the optical fibers from the ribbon in a shearing stroke of the reciprocal member. Cooperating with and hingedly mounted to the housing is a pair of cover members that are separated by a slit. Each cover member generally includes respective shearing blades that cooperate with the blades of the reciprocal member to effect the shearing of optical fiber ribbon. Maintaining pressure on the button or actuator, and at the same time pulling sheared optical fiber ribbon to its end, results in a lengthwise separation of optical fiber ribbon into two optical fiber subsets. Each of the two subsets has a number of optical fibers therein, for example, the two subsets may include six fibers each for a twelve fiber ribbon.
Conventional ribbon splitting tools have several disadvantages. First, if numerically different subsets of optical fibers are needed, the blades must be replaced with different sized blades that correspond to numerically different subsets of optical fibers. Blade replacement is a time consuming procedure, moreover, an expensive inventory of different sized blades must be maintained. Additionally, as the cover members and blades are separated, the covers may move independently of each other, consequently, the blades may become misaligned during the shearing stroke, possibly causing damage to optical fiber ribbon and optical fibers. Further, prior art shearing devices include many parts (e.g., multiple blades), some of which are machined metal parts, the manufacture and assembly of which is expensive and time-consuming. Still further, prior art splitting tools may not conveniently be utilized along a mid-span access point of a flat ribbon distribution cable due to the limited amount of space available. Typically, such task requires that a small breach or access point be made into the cable and the separation tool must thereafter be capable of being manipulated about the optical fiber ribbon for separation.
While conventional ribbon splitting devices are suitable for splitting a ribbon removed from a cable, it would be desirable to have a ribbon splitting tool capable of splitting a ribbon within a cable through a cable access point. Further, it would be desirable to have a universal ribbon splitting tool capable of splitting ribbons into distinct subsets of fibers. Still further, it would be desirable for a ribbon splitting tool to be able to work in cooperation with cable access point fiber grasping and severing tools.